grade 9 polynomials
posted by brooke .
7 (r+3s)  2(2r 9s)
I am having a hard time solving can anyone please help

Multiply the # outside the parenthesis by each item inside the parenthesis to remove the parentesis and then combine the like terms (r's & s's).

7r + 21s  4r + 18S
then combine like terms 
7r +21s  4r +18s
7r4r =21s+18s
3r+39
Does this sound correct. 
Yes , but 39s